CETO system: Using oceanic wave to generate clean electricity and desalinate water

Australia-based Carnegie Wave Energy Limited installed its CETO technology system off the coast of Garden Island in Western Australia in late 2014 to use oceanic wave to generate zero-emission electricity while desalinating oceanic water simultaneously.

Named after a Greek sea goddess, the CETO system is a technology for harnessing wave energy. It is different from other waver energy devices because it operates under the water making it invisible from the shore, away from breaking waves and beachgoers, and safer from large storms.

The CETO system is capable of converting ocean wave energy into zero-emission electricity while also desalinating ocean water. Furthermore, the system features an eco-friendly design making it attractive to marine life.

Carnegie Wave Energy has used its fifth iteration of the CETO system—the CETO 5—to demonstrate the commercial and large-scale use of wave energy under the Perth Wave Energy Project. This project is the first commercial-scale wave energy array in the world. Iy is connected to the grid and has the ability to produce desalinated water.

Photo credit: Carnegie Wave Energy Limited

The operational concept of the system is considerably simple. The CETO 5 includes three submerged 240 kW buoys and water pumps. Oceanic waves move the buoy, thus activating the pumps, pushing pressurised water through power turbines, while also feeding the same water into a built-in desalination system.

Carnegie Wave Energy is currently developing its CETO 6. This sixth iteration of the CETO system will feature 1000 kW buoys. Upon completion, the company is planning to launch a project capable of delivering 3MW of power.

Because diameter of the buoyant actuator has the most significant influence on power output, the company has increased this in CETO 6 to approximately 20 metre.

The CETO 6 will not only be larger. It will also incorporate the power generation offshore inside the buoy rather than onshore. Take note that the current CETO 5 generation being deployed for the Perth Wave Energy Project has an onshore power generation. Placing the power generation within the buoy removes the need to attach pumps, accumulators and other hydraulic components to the seabed, avoiding the requirement for offshore heavy lift vessel capacity and reducing the offshore installation and maintenance time and cost.

Improvements in the CETO 6 will allow the installation of the system further from the shore and in deeper water. This can also significantly increase the size of the commercial market for CETO and allow greater responsiveness in the CETO control system.

As of 2015 February 18 the Perth Wave Energy Project is providing electricity and desalinated water to HMAS Stirling in Garden Island, the largest naval base in Australia. Carnegie Wave Energy also has projects in Ireland, Bermuda, and Canada. Photo credit: Photos courtesy of Carnegie Wave Energy Limited